Surface electric railway.



IN VE IV TOR 274% 9% ATTORNEY PATENTED NOV. 19; 1907.

T. MAHONEY. SURFACE BLEGTVRIG RAILWAY.

iAPPLIOATION FILED JULY6. 1906.

- ternating current with TIMOTHY MAHONEY, OF SAN FRANCISCO, CALIFORNIA.

SURFACE ELECTRIC RAILWAY.

Specification of Letters Patent.

Patented Nov. 19, 1907.

Application filed July $1906. Serial No. 825,013.

To all whom'it may concern:

Be it known that I, TIMOTHY MAHoNEY, a citizen of UnitedStates, residing in the city and county of San Francisco and State of California, have invented new and useful Im 'provem'ents in Surface Electric Railways, of

which the following is a specification.

My invention relates to electric railways of the third-rail type.

Its object is to provide a system of distribution and a construction suitable for an ala third or single, sectional,-surface conductor-rail, and which systemwill be. perfectly safe, cheap to install, cheap vto maintain and which nil avoid elecitiliiolysis of water and gas pipes, mains and the The invention consists of theQarts and the construction of parts as hereinafter more fully describedand claimed, having reference to the accompanying drawings, in w.hich

Figure 1 is a view diagrammatically illus tr'ating the improved railway. Fig. 2 is a view in section of a switch.

A represents the ordinary track-rails traversed by the car 2, which is provided with the front and rear brushes or current collectors 3-4 traveling in contact with the siectional sulatcd sections. which are brushes 3-4 are third or conductor rail 5. This red 5 is arranged on the surface of the road bed and between the track rails and is divided intp inreferably less than one-half of the len th oi the car.

space from each other a distance slightly in excess of the length of any one section of a track-rail so that both brushes may not be on one section of the rail at the same time. Arranged between the abutting ends of adjacent sections, are the switch. mechanisms by which the current is cut into eachsectionof the conductor rail; as the car passes over a section the currentso cut in passin up through the, car to propel the same, and thence being returned through the wheel axle and track rails to the original source of power. These switches-are o'l' peculiar construction and form an essential feature of the present invention.

6 re resents a solenoid, the coil of which is suitab y wound to prevent the passage of an alternating current through it; in other words,each coil is-adapted as a choke-coil, as will be more fully explained hereinafter.

The-

track,

Each coil 6 is rovided with a reciprocating core 7, one enrFofwhich is provided with an annular trough 8 adapted to contact, when the coil is exclted to lift the core, with an annular contact-piece 9, which latter is connected through the wire 10 with the feedwire 11. The upper end of the core 7 carries a cup 12 to contain mercury, and is adapted, when the core 7 is lifted, to engage 'a corresponding contact 13 and close the circuit between wirelO and one section of the rail5; the contact 13 being connected by a suitable conductor 14 with one end of said section. The coil 6 has one terminal connected as shown at 15-with the same section of the rail is connected as at 16 with the adjacent end of an immediately preceding section of rail 5. It will thus be seen that the several rail sections are connected in series through the coils and are connected intermittently in multiple through the conductors 14-7 & 10 with a feed-wire 11. The coils, however, are adapted to pass only a direct current and opcrate. as choke-coils to the passage of an alternating current; it being the design of my invention to use an alternating current in the work circuit for running thefcars, and a dialternating-current (A-C) equipment. is

used on the car.

17 represents an'alternating current-generator or other suitable source of alternating current supply. From this source of supply the current is delivered to the main foodwire 18.

At suitable intervals along the line of Any suitable means carried by the car are are transformers 19 by which the.

and the other terminal of the coil 7 employed to excite the coils 6 successively.

I prefer'to use an alternating current to diroot-current motor enerator or rotary converter as 20 carried by the car; the motor having one terminal connected as at 21 with the AC conductor 22 on the car and the other terminal connected as at 23 with the.

return track rail throu h the car wheel. a he positive terminal of m3 direct current end of the generator 20 is connected through wire.

24 with the brush 3, and the negative terminal is connected through the wire 25 with the forward brush 4 (assuming the direction of travel of the ear to be as indicated by the ar row in Fig. 1).

The operation of the invention is as follows: With the car traveling in the direc tion of the arrow, or to the right, as in Fig. l, the direct current'generated by the generator 20 will pass through tliefwire 24 down through brush 3 to the section of rail 5 on which brush 3 is in contact, thence through the coil 6 inir'nediately in advance of brush 3 through the rail section in advance and up through brush 4 and wire 25 to return. This direct current creates an excitation in the coil 6, which is included in the circuit, thereby lifting the switch-member 7, closing the work-circuit between the rail section with which brush3 is in contact and the teed-wire 1-1. This work-circuit being of an alternating current will not ilow through the coil 6 by reason of the eounter-electroinotive-forcc which it induces, but will pass up through the brushes 3 into the car and thence to the controllers 26 and motors 27; afterwards returning through the car axles and track-rail. Each coil 6 is energized in turn as it is straddled by the brushes 3-4. As soon as the brush 3 passes beyond a coil, the direct-current circuit through this coil is broken, and also the alternating current circuit through the core or switch controlled by this coil is interrupted. With the coil becoming inert the switch-member 7 will drop down to original position on the spring 7 carrying its contacts 8-12 away from their respective ter niinals 9-13, and without the formation of any are at these points. Thus it will be seen that only one section of rail 5 will be alive at any one time, except for the short interval when the brushes span two insulated points in the sectional rail. The moment that the brush 3 passes oil of section, the section is left dead and perfectly safe for pedestrians and others.

The various coils 6 and their switch mechanisms along the line must be suitably housed to exclude moisture. I prefer to use a casing made in two sections 28-29, with the upper section 29 seating in the enlarged flanged end 30 of the lower section 28 and upon a disk 231 of suitable insulating mate rial which supports the coil 6. The casing and the protective disk 91 may be made ol: porcelain or terra cotta, or anvoiher cheap and durable insulating material. 1 haveniade these casings ol lerra cotla in a tual" practice. The bottom and top of the casing are provided \\'llli suitable outlets for ilurespective wires Hi- 14 16.

Having thus described my invention, l claim and desire to secure by Letters lai-- cut, is

i 1. A third-rail system comprising a pair l i continuous rails, rents connected to a supply conductor and track-rails, a sectional conductor-rail, a car traversing the track-rails and provided with altern ating'current-e quip ment, swit eh-n iagnet coils connected in series with adjacent sectional rails, said coils having a large reactance'to oppose the passage of alternating currents, a source of alternating current supply, switch mechanism operated by said switch-magnet-coils to close a circuit between said source of alternating current-supply and the rail sections, and means carried by the car for supplying said magnet-coils with a directexciting current.

2. A third-rail system compr sing in combination a. pair of track rails at" least one of which is electrically continuous, acar provided with alternating-current equi inent traversing said track-rails, a sectiona conductor rail, brushes on the car engaging sections of said conductor rail, solenoids connected in series with adjacent rail sections, said solenoids having a large reactance to oppose the passage of alternating currents, an alternating-current conductor, a source of alternating currents connected with said conductor. and the track-rails, a series of transformers arranged along the line of track and having their primary coils connected between said conductor and said continuous ends of adjacent sections connected through switch n'iagnets whose reactances oppose the passage of alternating currents, feeders connected with said su ly conductor, and means actuated by said switch magnets for connecting said feeders with said sectional rail sections. p

I 4. In an electric railway system, the combination of trackway having electrically a source of alternating curwith said rails, a sectional rail having the ends of adjacent sections connected through switch magnets whose reactances oppose the passage of alternating currents, l'eeders connected with suit actuated by said switch magnets for connecting said l'eedcrs with said sectional rail sections, and a car adapted to traverse said trackway provided with. an alternating current. equipment and having a direct current source to energize said switch-magnets.

in an electric railway system, a switch 1 supply conductor, means lhehanism oomprising an insulating casing In testimony whereof I have herelinto sot 'having -telescopmg sectioils; an insulatin my hand in presence of two subscribing wit- 10,

stlsppcilrted' upon the lowelt-siectiog an] nesses. I e t e -u' er section, a so enoi coi t r 5 supported 111501 1 said disk, fixed contacts se- TIMOTHY MAHONEY' :oured respectively in the upper part of each Witnesses:

section,"a1id asolenoid core arranged to make A. A. CALDWELL, contact with said fixed contacts. a HUGH J. MOISAAC. 

